Method of making reinforced concrete buildings



y 1945- A. w. HEDGREN 2,379,636

METHOD OF MAKING REINFORCED CONCRETE BUILDINGS Filed Oct. 17, 1941 INVENT OR.

Eu en a Patented July 3, 1945 METHOD OF MAKING REINFORCED CONCRETE BUILDINGS Arthur W.

Hedgren, Pittsburgh, Pa., assignor to Robertson Company, corporation of Pennsylvania Pittsburgh, Pa., -a

Application October 17, 1941, Serial No. 415,393

2 Claims.

This invention relates to a reinforced concrete building and to a method of making the same.

One object of the invention is to produce a novel reinforced concrete building which may be erected at minimum expense and which is particularly adapted for embodiment in the building structure for prefabricated steel flooring.

A further object of the invention is to provide a novel method of constructing a reinforced concrete building by which economies in the handling and pouring of the concrete may be effected and which lends itself to the embodiment in the building of metal flooring of the type illustrated in the United States patents to Young, Nos. 1,867,433 and 1,855,082.

Another object of the invention is toprovide a novel and improved prefabricated floor supporting concrete beam or joist which lend itself particularly for use in the construction of a reenforced concrete building embodying the present invention.

With these general objects in view. and such others as may hereinafter appear, the invention consists in the reinforced concrete building and method of making the same and in the floor supporting concrete beam or joist, and also in the various structures, arrangements and combinations of parts hereinafter described and particularly defined in the claims at the end of this specification.

In the drawing illustrating the preferred embodiment of the invention, Flg. 1 is a perspective view of portions of a reinforced concrete building embodying the invention with portions broken away to illustrate details of the novel construction; Fig. 2 is a plan view illustrating a typical bay of such a building; and Fig. 3 is a cross-sectional detail of a prefabricated concrete floor supporting beam or joist preferably employed in the construction of the present building Prior to the present invention diiilculty has been experienced in the installation of the cellular steelfiooring illustrated in the Young Patents Nos. 1,867,433 and 1,855,082 in reinforced concrete building structures because of the dimculty in the production of sufliciently accurate and level surfaces upon the concrete floor supporting joists or beams. In addition, the fastening of the metal flooring in place has required special bolts and fixtures cast in the beams, all

building structure.

inforced concrete building structure is produced embodying a novel reinforced concrete floor supporting beam or joist which is characterized by the provision as an integral part of such reinforced concrete member of a metal, preferably a steel floor supporting member disposed at the surface of the reinforced concrete beam or joist. Such a metal floor supporting member may comprise one and preferably two structural steel bars cast integrally with the reinforced concrete beam or joist to provide the same with a metal floor. supporting member at the upper surface thereof. The present reinforced concrete building structure may, and preferably will be produced by framing su'ch novel reinforced concrete beams into the usual concrete girders and a prefabricated metal flooring preferably comprising the cellular steel flooring forming the subject matter of the aforesaid Young patents may and preferably will be laid upon and fastened to the metal floor supporting members in the upper surof which contribute to the ultimate cost of the I face of the novel reinforced concrete floor supporting beamsor joists. In accordance with the preferred method of erecting the present building the reinforced concrete joists are framed intov the girder forms and then the metal floor erected upon the joists providing a working platform which facilitates the pouring of the concrete forming the girders and also the concrete forming the vertical columns or pillars, and in addition the usual concrete floor fill or slab which is usually provided over the surface of the metal floor. The fact that all of these pouring operations may be conducted in a continuous manner contributes greatly to the economical production of the building and at the same time insures the production of the most satisfactory bonding of the floor slab, the girders, the floor joists, and the columns into an integral concrete mass.

Referring now to the drawing, I0 represents a metallic flooring preferably of cellular structure, as illustrated and described in the United States patents to Young, Nos. 1,855,082, issued April 9, 1932, and 1,867,433, issued July 12, 1932. As herein shown, the illustrated metal floor comprises a flat sheet metal lower member I2 and a corrugated metal upper member I welded thereto, and the unitary flooring thus assembled may,

In accordance with the present invention a re- 66 other analogous uses, all as illustrated and described in said United States patents to Young, Nos. 1,855,082 and 1,867,433, and in United States Patent No. 2,182,686, issued December 5, 1939, to which reference is made.

In practice such flooring may and preferably will be provided with a concrete top fill during the erection of the building, the metallic flooring l serving as the base or load bearing member, as fully illustrated and described in the aforesaid patents.

In accordance with the: present invention, the prefabricated metal flooring ill is supported by and secured to a plurality of spaced and horizontally extended floor supporting joists l6 preferably comprising pre-cast reinforced concrete beams, each provided with a metallic upp r surface inserted in and cast integrally with the prefabricated concrete beam to form a part thereof. As shown in detail in Fig. 3, each beam is preferably formed in the general shape of an I-beam, the lower section being provided with shear bars or reinforcing rods I8, 20 and the upper portion being provided with a pair of steel angle bars 22, 24, set back to back preferably in spaced relation and having one leg of each set substantially flush with the top of the concrete beam. The angle bars 22, 24 and the rods i8, 20 may and preferably will be joined by diagonal shear rods 25 welded thereto, as shown in a broken away section of the joist in Fig. 1. It will be apparent that other forms of structural steel members may be embodied in the pre-cast concrete joist memher in like manner in order to present a metallic surface at the top of the beam upon which the metallic flooring sections may be laid and secured in predetermined and level relation.

In accordance with the present method of constructing a reinforced concrete building, the forms for the columns 26 and for the girders 28, see Fig. 2, are first erected. As shown in Fig. 1, the wooden form for a. girder is indicated by the numeral 30, the integral and expanded portion 32 thereof representing a part of the form for the vertically extended column or pillar 26. As herein shown, the forms are supported by the shoring members indicated generally by the numeral 33. The ends of the joists 16 are extended and framed into the girder forms as shown and in the desired spaced relation. The joists as thus placed are accurately leveled, using the metallic members 22, 24 thereof as leveling guides so that when the metal flooring is subsequently erected upon the joists and supported directly on the metal members 22, 24-a level flooring is insured, and a uniform bearing is afforded for the metal floor.

The prefabricated flooring units ID are now placed directly upon the precast joists l6 and transversely thereof extending across the bays from one joist to an adjacent joist. As illustrated in Fig. 1, in laying the flooring, the flooring sections l0 which are laid adjacent the forms for the frame structure are placed with their longitudinal side edges 35 in alignment with the sides of and in engagement with the top edges of the forms for the girders so that upon pouring the concrete and removing the forms as will be hereinafter described, the edges of the flooring sections will be bonded with the concrete frame structure.

The metallic flooring sections it! are then welded or otherwise fastened to the metallic members 22, 24 formed in the surface of the joists l6 as the sections are laid down. The flooring sections are preferably laid end to end to form unobstructed ducts as illustrated and described in the Young patent, No. 1,867,433, above referred to, adjacent edges of the sections being Joined together by welding or otherwise to form a unitary flooring panel extending across the entire length of the building. Suitable cross ducts or electrical headers, not shown, may also be incorporated in the flooring panel during the installation thereof if desired, impart maximum electrical flexibility to the floor, when the cells are used as wiring conduits, all as set forth in said Young patents above referred to.

After the metallic flooring has been thussecured in place, metal reinforcing rods 24, 26 for the girders 28 and the reinforcing rods 28 for the vertical columns 26 may be placed in position preparatory to pouring the concrete. As herein shown, the lower horizontally disposed reinforcing rods 36 for the girders are supported in U- shaped hangers 40 having laterally extended portions 42 resting upon the edges of the adjacent flooring sections Ill. The upper reinforcing rods 34 for the girders may rest upon the top of the ends of the joists l6 extending within the forms and adjacent the vertical legs of the U-shaped hangars, as shown, whereby when the concrete has been poured to form the girders, columns, and floor slab an efficient reinforced concrete structure is formed uniting the columns, girders, joists, and the concrete floor slab for the top of the metallic flooring into a unitary structure.

From the description thus far it will be observed that the precast reinforced concrete joist, havinga metallic member cast in the upper surface thereof, provides a substantially level and uniform surface upon and to which the metal flooring sections Ill may bear to transmit its load and be conveniently secured. It will be observed that the cellular metal flooring may be permanently installed prior to pouring the concrete so that all work to be performed or installed in or under the metal flooring l0 may he proceeded with directly using the flooring as a working platform. The concrete 44 may be poured into the forms, using the preinstalled flooring as a platform, the extended ends of the precast joists becoming embedded and securely anchored in the frame structure as the concrete hardens.

During the single pouring operation the concrete for forming the columns and girders may be poured, using the metal flooring as a working platform, and immediately thereafter and as a part of the same pouring operation the top flll or floor slab may be poured upon the metal flooring. This contributes to the economical handling of the concrete and results in substantial economies in the ultimate cost in constructing the building. In addition, a unitary concrete structure is produced including the columns, girders, floor slab and the reinforced concrete floor supporting joists. The fact that the metal floor may be levelled upon and conveniently secured to the metal surfaces of the reinforced concrete floor supporting joists contributes to the production of a most satisfactory structure.

The novel precast reinforced floor supporting joist finds particular use at the present time because of the diillculty in obtaining structural steel. However, although it is preferred to embody in the building the precast concrete floor supporting joists as has been illustrated and described, nevertheless it will be understood that in its broader aspects the invention contemplates the use of standard structural steel members as the preferred supporting joists in a reinforced concrete frame structure if such use is found to be advantageous.

, While the preferred embodiments of the invention have been herein illustrated and described, it will be understood that the invention may be embodied in other forms within the scope of the following claims.

Having thus described the invention, what is claimed is:

1. In the'method of constructing a reinforced concrete building having a metal flooring provided with a concrete top fill, the steps comprising erecting forms for the frame structure including the forms for the columns and girders, placing prefabricated concrete floor supporting joists having a metallic floor supporting mem-' ber in their upper surfaces with their ends supported by and extended within said forms, erecting a metallic flooring upon and extending over said floor supporting joists, welding said metallic flooring to the said metallic floor supporting members of said prefabricated joists, and then pouring the concrete mixture to fill said forms and to provide the concrete top fill for said floor in a continuous operation.

2. In the method of constructing a reinforced concrete building having a metal flooring provided with a concrete top fill, the steps comprising erecting forms for the frame structure including the forms for the columns and girders, placing prefabricated concrete floor supportingjoists having a metallic floor supporting member in their upper surfaces with their ends supported by and extended within said forms, leveling said floor supporting joists using the metallic upper surface thereof as leveling guides, erecting a metallic flooring upon and extending over said floor supporting joists, welding a metallic flooring to the said metallic floor supporting members of said prefabricated joists, and then pouring the concrete mixture to fill said forms and to provide the concrete top fill for said fioor in a continuous operation.

AR'I'HUR. W. HEDGREN. 

